May likely be the senfgurken recipe posted by Fear_Itself. But that recipe does not include cinnamon except for whatever is in the optional pickling spice.
Do you remember if she canned them for shelf-stable storage, or kept them in the refrigerator? Here’s a recipe for refrigerator pickles. It does not call for peeled, seeded cucumbers, though.
I have a vague recollection of seeing a recipe similar to the one described; I’ll check my canning cookbooks when I get a chance to see if I can find it.
Edited to add: Are you sure she used cucumbers? In many ways it sounds like you’re describing pickled watermelon rind.